Aligarh district is a district of Uttar Pradesh with its administrative headquarters located at Aligarh city. The city is famous as Tala Nagri meaning "City of Locks" since there are many lock industries in the city. The history of the district till 12th century is quit vague. Prior to 18th century Aligarh was popularly called by its former name i.e. Kol or Koil. But the name Kol covered both the city as well as the entire district. There are many theories regarding the origin of its name. It is believed that the people, who came from Kampilya (a place), founded the city and named it Kampilgarh. In course of time its name Kampilgarh changed to Koil and then Aligarh, the current name. On the other hand according to an 1875 gazetteer written by Edwin T. Atkinson, the place got its name Kol after the name of a great Asura (demon) “Kol” slewed there by Balarama and with the assistance of the Ahirs, subdued this part of the doab. In another account, Atkinson figure out that Kol was established by the Dor tribe of Rajputs in 372. Later it is proved by an old fort, the ruined Dor fortress, which lies at the heart of the region. During the past period Aligarh fort, the most prominent centre of attraction was also known as Koil fort. At that time Surajmal, a Jat ruler captured the Koil fort with help of Jai Singh from Jaipur and the Muslim army. He then renamed it as Ramgarh. Lastly, Najaf Khan, a Shia commander came to the place and occupied it and he changed the name of the fort to its present name of Aligarh. In the year 1804 Aligarh was emerged as a separate district in the map of Uttar Pradesh state.

Qurratulain Hyder, an illustrious Indian Urdu novelist and short story writer, an academic, and a journalist was born on 20th January, 1927 at Aligarh city. She became famous for her magnum opus, Aag Ka Dariya (River of Fire), a novel first published in Urdu in 1959. She was honoured by many prestigious awards such as Sahitya Akademi Award in 1967, Jnanpith Award  in 1989 and Padma Bhushan in 2005.

Geographically, the district lies at 27°89'N latitude, 78°07'E longitude and 180 m altitude. In the year 2021, there was a total 1.83% forest area of total geographical area. The district encompasses a geographical area of 3,650 sq. km. and in terms of geographical area it occupies 32nd rank in state and 331st rank in India. It is enclosed by districts of Gautam Buddha Nagar  and Bulandshahar on the north, Mathura district and Mahamaya Nagar district on the south, Buduan district and Kanshi Ram Nagar District on the east and Haryana on the west. The climate of the district can be categorised as humid sub tropical climate. Natives of the district experience extreme all the three seasons i.e. summer, monsoon and winter. Summer of the district is very hot hot and dry whereas the winter is fairly cold. Most of its rainfall occurs in the monsoon season. The actual rainfall in the district was 669.3 mm in the year of 2021-22.

Administraton wise, the district is divided into 5 tehsils namely Koil, Khair, Atrauli, Iglas and Gabhana. These tehsils are further divided into 12 blocks. There are 1 Lok Sabha seat and 7 Assembly constituencies in the district. Moreover, the district has a total number of 5 sub-districts, 24 towns and 1,199 villages. The administrative language in the district is Hindi.

According to 2011 census the district has a population of 36,73,889 including 19,51,996 were males and 17,21,893 were females. The district has a sex ratio of 882 females for every1000 males. The population density in the district is 1,007 persons per sq. km. During the year 2001-2011 the population growth rate in the district was 22.78% out of which 21.44% were males and 24.33% were females. As per 2011 census the major religion in the district is Hindu with 79.05% of the total population. According to 2011 census the main language that speaks in the district is Hindi with 94.53%. In the year 2020 the number of live births in the district was 94,096 including 47,587 were males and 46,509 were females. In the same year the number of deaths in the district was 14,152 including 9,039 were males and 5,113 were females.

The economy of the district is mainly dependent on agriculture. The agro based industries are the chief industries in the district. Some of its important agricultural products are paddy, pearl millet, maize, pigeon pea, different types of pulses, barley, potato, sugarcane, etc. Every year a huge chunk of revenue comes from these agricultural products. On the other hand not only agriculturally but also industrially, the place has a good name in the state of Uttar Pradesh. Aligarh is popular for its lock industries which are exported to different parts of the world. Johnson & Co. established in the year 1870 was the first English lock firm in the district. The district is renowned for its extra ordinary brass hardware and sculpture. Some of the notable industies in the district are Heinz-sauce manufacturing unit in Manzurgarhi, Satha sugar factory on the Aligarh-Kasimpur Power House route, a cement factory of Ultra Tech Cement company, Indian Oil Bottling Plant at Andla, Wave Distillery (Kingfisher bear) at Atrauli in Aligarh and may more. In the year 2020-21 the gross domestic product in the district was Rs. 30,91,573 lakh at Current Price and Rs. 19,25,378 lakh at Constant Prices during the year 2011-2012. The Net Domestic Product in the district during the period 2020-21 was Rs. 27,51,057 lakh at Current Price and Rs. 16,67,061 lakh at Constant Prices in the year 2011-2012. The Per Capita Income or NDDP, At Factor Cost in the district during the period 2020-21 was Rs. 63,609 at Current Price and Rs. 38,545 at Constant Prices in the year 2011-2012.

The district is fortunate enough to have the reputed central university named Aligarh Muslim University which offers more than 300 courses in both traditional and modern fields of education. Aligarh Muslim University is a fully residential university with almost 13 faculties, 7 constituent colleges, 15 centres, 3 institutes and 10 schools. As per 2011 census the literacy rate in the district is 67.52% out of which 77.97% were males and 55.68% were females. The total number of literates in the district is 20,92,567 including 12,83,380 were males and 8,09,187 were females.

Kalyan Singh, an eminent Indian politician and the present governor of Indian state of Rajasthan was born on 5th January, 1932 at Atrauli in the district. He has served as the Chief Minister of Uttar Pradesh for two terms i.e. 24th June, 1991-6th December, 1992 and 24th June, 1991-6th December, 1992. He is a member of Bharatiya Janta Party. Bijendra Singh, a distinguished Indian politician and a member of 14th Lok Sabha was born on 25th December, 1956 at Dhonda village in the Aligarh district. He had also been elected as MLA for five times from Iglas constituency, Aligarh. He is a member of Indian National Congress.

During the year 2021, there were 17,00,000 domestic tourists who visited these places of the district. The district has numerous centres of attraction which allures many travellers from different parts of the country. Shekha Jheel, a lake (jheel) located near the Shekha village, in the district is notable for varieties of migratory birds. Maulana Azad Library, the central library of Aligarh Muslim University is a building of seven-stories surrounded by 4.75 acres (1.92 ha) of lawns and gardens. Aligarh Fort, one of the strongest forts in India is located in the Aligarh city. It consists of a regular polygon, surrounded by a very broad and deep ditch. Khereshwar Temple, the Birth Place of Swami Shri Haridas ji and "Sai Mandir" at Sarsol on G.T. Road are the two remarkable temples in the district. There are four key temples at four corners of the Achal Taal and all the four temples are Hindu Siddh Peeth. The Tika Ram mandir at centre point is also a renowned temple of the city. Some other important places of interest in the district are Clock Tower, Dharnidhar Sarovar, Jama Masjid, etc.